Question

Mrs. lim is y year old.she was 25 year old when her son was born. Their total age in 12 years’ time will be n years.

Answer 1

let x be the age of her son

y = 25 + x

y - 25 = x

(y + 12) + (x + 12) = n

y + x + 24 = n

y + y - 25 + 24 = n

2y - 1 = n

sub

2(38)-1 = n

n = 78